The present invention relates generally to a low-power transmitter and, more particularly, to a low-power and battery-free transmitter for remote control.
Portable electronic devices, such as smart phones, tablet computers or the like, would have taken an important part in daily life. Various application software have been created or developed to work with a portable electronic device to perform certain functions, for example navigation, video games, video/audio display, electronic commerce, etc.
Among the aforesaid application software, one is developed and performed by a portable electronic device to remotely control another electronic products. FIG. 1A is a schematic block diagram of a conventional remote control system A which employs a portable electronic device 11. Referring to FIG. 1A, the remote control system A may include a remote control 1 and an electronic device 2. The remote control 1 may further include a transmitter 10 which can be connected to the portable electronic device 11 through an audio connector 12. Accordingly, a audio signal may be sent from the portable electronic device 11 to the transmitter 10. The audio signal from the portable electronic device 11 may have a predefined format so that the audio signal may serve as a modulation signal and/or control signal. The electronic device 12 may contain a receiver (not shown) to receive the modulation signal/control signal from the portable electronic device 11.
FIG. 1B is a block diagram of the remote control 1 in the remote control system A of FIG. 1A. Referring to FIG. 1B, the transmitter 10 of the remote control 1 may include a transmission module 14 configured to send out a modulation signal, such as a radio-frequency (RF) signal or an infrared (IR) signal. The transmission module 14 may consume lots of power and thus require an external power supply. Accordingly, the transmitter 10 may further include a battery 15, which may inevitably increase the size and cost of the transmitter 10.
It may therefore desirable to have a remote control which is equipped with a light and compact transmitter without external power supply.